Too long, too slow, too boring.
10 minutes is a pretty long time for any flash video. Too long really, unless it's a very good one. I know you wanted it to fit with the song, but the graphics weren't that great, and so much of it was just the same movie clips and a little bit of tweening, being shown to me for like a minute. It gets pretty boring.
And in the end, this is kind of a minor thing, but you say he's happy in his new life, but never truly happy, cause of the dead family. I kinda think with this type of thing it would be better to say he's sad about his family first, and then say, but he's happy in his new life. Seems like a pretty carefree cartoon overall, which is appropriate for a rabbit, and then you sort of end it saying "but even rabbits lives suck".